ABSTRACT This application is being submitted in response to NOT-DA-19-003 as an administrative supplement to parent grant R21 DA045092 (PI: Ramirez). The overarching objective of the parent grant is to evaluate cannabis identity, or the extent to which one views cannabis use as part of their identity, as a cognitive and developmental risk factor for adolescent cannabis misuse. This will be done by developing Implicit Association Tests (IATs) that aim to measure adolescent's implicit associations between cannabis and one's identity. These IATs will be evaluated as risk factors by examining concurrent and prospective associations between IAT scores and cannabis misuse reports. The current supplement proposes to advance efforts to combat the opioid epidemic in the United States through examination of risk factors included in the parent grant and by developing novel implicit measures of opioid-related cognitions to evaluate as risk factors for opioid misuse. The parent grant is well situated to advance these efforts given the investigation of cannabis identity in a sample of adolescents (ages 15-18), who are screened into the study based on prior cannabis use. Given prior research indicating cannabis use as a risk factor (and not a protective factor) for opioid use, the addition of opioid-related measures to the parent grant will allow for examination of cannabis identification as a risk factor for willingness to misuse opioids among adolescents. The supplemental research will also add focus groups to qualitatively assess adolescent attitudes regarding the opioid epidemic in the United States and in their surrounding community. Findings from these focus groups will directly inform the content to be included in the development of novel IATs that aim to measure implicit associations between opioids and other constructs. Rationale for the development of these measures comes from a considerable line of research demonstrating IAT scores as predictors of misuse behavior for other substances (e.g., alcohol, tobacco). These opioid-related IATs will be added to online assessments included in the parent grant and will be completed by an additional 50 adolescent (ages 15-18) cannabis users to examine these IATs as risk factors for opioid misuse. Aims of the supplemental research directly relate to Aims of the parent grant and include: 1) Qualitatively assess late adolescent attitudes and perceptions regarding the opioid epidemic; 2) Examine cannabis identity IATs (assessed in the parent grant) as concurrent and prospective predictors of willingness to misuse opioids; and 3) Develop two novel opioid-related IATs: one measuring associations between opioids and one's identity (i.e., `opioid-identity IAT'), and another measuring associations between opioids and perceptions of harm (i.e., `opioid-harm IAT'). We will compare the IATs with regard to internal consistency and validity in predicting concurrent willingness to misuse opioids. The research findings will advance theory and efforts combating the opioid crisis by examination of potential risk factors for opioid misuse among adolescents that could be untapped targets for prevention strategies.